David Knight and Finn Williams have been investigating what they call "minor development" in the field of architecture and urban planning for several years now, and their discoveries are absolutely fascinating. Last year they published a book called SUB-PLAN: A Guide to Permitted Development, exploring the world of building extensions, temporary structures, outdoor spaces, and other minor acts of home construction that fly beneath the radar of official town planning.

"How far does planning control what we build? And what can we build without planning?" the authors ask. "SUB-PLAN explores the legal possibilities of building outside the limits of legislation."

The UK planning system has been swamped by minor applications for household extensions and outbuildings that cause a backlog of bureaucracy and dominate the limited resources of local planning authorities. On 1 October 2008 the government introduced changes to the General Permitted Development Order 2 to reduce the number of minor applications by expanding the definition of what can be built without planning permission.

But, they add, "are the implications of minor development more significant than planners imagine?"

[Images: Courtesy of David Knight and Finn Williams].

Knight and Williams will be participating in a public conversation next week in London, sponsored by the Architecture Foundation; called Permitted Development: The Planning Permission We Already Have, it will be an example of what we might call legislative forensics, looking into the law books—and the urban planning guidelines—to see what architectural possibilities already exist in the present day for residents to explore.

In that previous sentence, I almost wrote "for residents and homeowners to explore"—but I wonder if you really need to be a homeowner to take advantage of these unpublicized zones of building permission? Is simply being a citizen enough, or must you own property to participate in the realm of minor architecture? Or is there even an unacknowledged world of building practices legally open to construction by non-citizens—by people who, legally speaking, reside nowhere?

In the intersection between architecture and permission, what spaces are possible and who has the right to realize them? What are the possibilities for architectural insurrection—or, at the very least, aesthetic experimentation?

[Image: An awesome glimpse of "the permission we already have," courtesy of SUB-PLAN by David Knight and Finn Williams; view larger].

In Sweden, for instance, there is a type of small garden shed known as the friggebod, named after Birgit Friggebo, Sweden's former housing minister. "The term is a wordplay based on the common term bod: (tool) shed; shack," Wiktionary explains. "The friggebod reform implied that anyone could build a shed of maximum 10 square meters on their premises without obtaining a construction permit from the municipality. In Sweden, the reform became a widely popular symbol of liberalization. From the onset of 2008, the area was increased to 15 square meters."

These autonomous planning zones, so to speak, open up architectural production to non-architects in a possibly quite radical way. So how do we take advantage of them?

[Images: Another mind-bending example of "the permission we already have," courtesy of SUB-PLAN by David Knight and Finn Williams].

Though apparently at the humble end of the planning system, recent changes to Permitted Development rights are a treasure trove of architectural potential. The new breed of lean-tos, loft conversions, sheds and summerhouses they allow could have far-reaching and surprising consequences for UK towns and countryside. Finn Williams and David Knight will present recent projects which explore and exploit Permitted Development rules.

I'd love to hear how this goes, in case anyone there can report back. To be honest, I think this type of research is both jaw-dropping and urgently needed elsewhere. What unknown architectural permissions exist for the residents of Manhattan, LA, Beijing, São Paulo...?

What future DIY architectures have yet to arise around us—and when will we set about constructing them?